The instant invention relates to apparatus for inserting sheet materials into envelopes, and more particularly to a device for opening an envelope for the insertion of a collation being 1/4 inch or more in thickness.
Envelope stuffing machine, such as those shown in U.S. Pat. Nos. 4,169,341 and 4,337,609, both assigned to the assignee of the instant application, generally include: a conventional structure for delivering an envelope, with its address panel oriented upwardly and its flap opened, to a registration gate at an enclosure inserting station; conventional structure for timely opening the delivered envelope, including a plurality of fingers known in the art as stripper fingers, which are insertable into the throat of the envelope for opening the same; and conventional structure for inserting an enclosure into the opened envelope. Typically, the envelope opening structure includes a plate which acts as a ledge upon which the flap of the envelope is located when it is delivered to the inserting station. Moreover, one or more rigid finger members, known in the art as depressor fingers, are fixedly attached to the framework of the inserter apparatus and disposed in overhanging relationship with respect to the envelope's address panel, for depressing the body of the envelope downwardly against the resistance afforded by the envelope flap ledge to thereby partially open the throat of the envelope to facilitate insertion of the stripper fingers into the envelope.
Operators of the conventional inserters have experienced difficulties with them due to the aforesaid fixed depressor fingers tending to prevent delivery of the envelope to the registration gate. As a result, many operators have been bending the depressor fingers away from the path of travel of the envelope to ensure delivery to the registration gate, as a result of which the force exerted on the envelope by the depressor fingers is reduced and the envelope is insufficiently depressed to permit entry of the stripper fingers into the envelope for opening the same. Accordingly, misfeeds resulting from improper envelope registration and failure to open the envelopes have been found to be directly attributable to the provision of the fixed depressor fingers. The aforesaid U.S. Pat. No. 4,337,609 taught a partial solution to the problems generated by fixed depressor fingers y providing movable depressor fingers which normally hold the depressor fingers out of the path of travel of the envelope and for moving the depressor fingers into engagement with the envelope when a connective solenoid is enabled.
However, problems still persist using the movable depressor fingers. Thus, the assignee of instant invention provided an envelope opening apparatus in connection which a belt device for the feeding of enclosures which employs only a pair of orbital stripper claws and does not require the use of any depressor fingers, fixed or movable, and the substantial amount of apparatus associated therewith. The aforementioned envelope opening apparatus is described in co-pending application Ser. No. 242,566 filed Sept. 12, 1988. Experience has now shown that insert collations of 1/4 inch thickness or greater have a greater tendency than thinner collations to cause jams on their being inserted into an envelope. Accordingly, the instant invention provides an envelope throat opening blade which allows collations of 1/4 inch thickness or greater to be inserted by the use of belts into envelopes without a greater tendency for the creation of jams than with thinner collations, while at the same time not impeding the processing of thinner and/or lighter collations. The instant invention is particularly helpful when the collation is being fed into light or thin envelopes.